The present invention is related to the field of remote identification devices, in particular, the remote identification and maintenance of service records for various pieces of downhole and surface oilfield equipment.
1. Field of the Invention
The present invention relates generally to the field of identifying downhole and surface oilfield equipment for the purposes of maintaining usage records for such equipment.
2. Background of the Invention
The exploration, development and completion of an oil or gas field requires numerous pieces of equipment and materials such as casing, drill pipe, packers and other equipment. The cost of this equipment is relatively high. Accordingly, it is desirable to reuse many pieces of equipment for subsequent drilling and development operations. However, equipment undergoes considerable stress during drilling and completion operations. Components such as drill pipe may suffer from material fatigue which may ultimately result in failure of the drill pipe. The failure of a joint of drill pipe when downhole will require a suspension of drilling operations to recover the remainder of the drill string and other related equipment. It will be appreciated that the recovery of a drill string can be an expensive and time-consuming operation. Accordingly, it is desirable to maintain a service record relating to various pieces of equipment, such as drill pipe, for the purposes of determining fatigue and other factors relating to the use of equipment.
A number of methods have been utilized in an attempt to track service time information relating to pieces of oilfield equipment. U.S. Pat. No. 4,578,991 discloses a means for identifying drill pipe utilizing concentric rings of ferrous and non-ferrous material to create an identification code for the particular piece of drill pipe and a sensing means which detects the bands as the drill pipe passes the sensing means. The method disclosed therein suffers from limitations in the identification system in that only so many concentric rings may be mounted on any one length of drill pipe. Further, the disclosure calls for a stationary detector.
U.S. Pat. No. 4,061,967 also disclosed a means of identifying drill pipe utilizing a stationary electromagnetic detector "shoe" which sensed magnetic and non-magnetic inserts placed on the periphery of a tool joint pipe. However, the system disclosed therein required that the pipe be identified as it traversed the detector on its way downhole. It will be appreciated that in order to remove a joint of drill pipe which has exceeded its nominal service time, the joint will have to be uncoupled from the remainder of the drill pipe string. U.S. Pat. No. 4,202,490 also disclosed a similar identification system also utilizing magnetic and non-magnetic inserts dispersed around the periphery of a pipe joint and a detecting coil. This disclosure suffers from the same problems as U.S. Pat. No. 4,061,967.